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Split PIA into PIA/VIA6522

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This commit is contained in:
Seth Morabito 2014-08-12 15:06:08 -07:00
parent 45f596e0d4
commit 742e3a1027
3 changed files with 98 additions and 38 deletions
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38
src/main/java/com/loomcom/symon/devices/Pia.java
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@ -23,45 +23,19 @@
package com.loomcom.symon.devices;
import com.loomcom.symon.exceptions.MemoryAccessException;
import com.loomcom.symon.exceptions.MemoryRangeException;
public class Pia extends Device {
public static final int PIA_SIZE = 16;
public abstract class Pia extends Device {
private static final int ORB = 0;
private static final int ORA = 1;
private static final int DDRB = 2;
private static final int DDRA = 3;
private static final int T1C_L = 4;
private static final int T1C_H = 5;
private static final int T1L_L = 6;
private static final int T1L_H = 7;
private static final int T2C_L = 8;
private static final int T2C_H = 9;
private static final int SR = 10;
private static final int ACR = 11;
private static final int PCR = 12;
private static final int IFR = 13;
private static final int IER = 14;
private static final int ORA_H = 15;
private final String name;
public Pia(int address) throws MemoryRangeException {
super(address, address + PIA_SIZE - 1, "PIA");
}
@Override
public void write(int address, int data) throws MemoryAccessException {
; // No-Op
}
@Override
public int read(int address) throws MemoryAccessException {
return 0;
public Pia(int startAddress, int endAddress, String name) throws MemoryRangeException {
super(startAddress, endAddress, name);
this.name = name;
}
@Override
public String toString() {
return null;
return name;
}
}

90
src/main/java/com/loomcom/symon/devices/Via6522.java Normal file
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@ -0,0 +1,90 @@
package com.loomcom.symon.devices;
import com.loomcom.symon.exceptions.MemoryAccessException;
import com.loomcom.symon.exceptions.MemoryRangeException;
/**
* Very basic implementation of a MOS 6522 VIA.
*
* TODO: Implement timers as threads.
*/
public class Via6522 extends Pia {
public static final int VIA_SIZE = 16;
enum Register {
ORB, ORA, DDRB, DDRA, T1C_L, T1C_H, T1L_L, T1L_H,
T2C_L, T2C_H, SR, ACR, PCR, IFR, IER, ORA_H
}
// Ports A and B
private char[] portData = {0, 0};
private char[] portDirections = {0, 0};
public Via6522(int address) throws MemoryRangeException {
super(address, address + VIA_SIZE - 1, "MOS 6522 VIA");
}
@Override
public void write(int address, int data) throws MemoryAccessException {
Register[] registers = Register.values();
if (address >= registers.length) {
throw new MemoryAccessException("Unknown register: " + address);
}
Register r = registers[address];
switch (r) {
case ORA:
case ORB:
case DDRA:
case DDRB:
case T1C_L:
case T1C_H:
case T1L_L:
case T1L_H:
case T2C_L:
case T2C_H:
case SR:
case ACR:
case PCR:
case IFR:
case IER:
case ORA_H:
default:
}
}
@Override
public int read(int address) throws MemoryAccessException {
Register[] registers = Register.values();
if (address >= registers.length) {
throw new MemoryAccessException("Unknown register: " + address);
}
Register r = registers[address];
switch (r) {
case ORA:
case ORB:
case DDRA:
case DDRB:
case T1C_L:
case T1C_H:
case T1L_L:
case T1L_H:
case T2C_L:
case T2C_H:
case SR:
case ACR:
case PCR:
case IFR:
case IER:
case ORA_H:
default:
}
return 0;
}
}

8
src/main/java/com/loomcom/symon/machines/SymonMachine.java
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@ -26,11 +26,7 @@ package com.loomcom.symon.machines;
import com.loomcom.symon.Bus;
import com.loomcom.symon.Cpu;
import com.loomcom.symon.devices.Acia;
import com.loomcom.symon.devices.Acia6551;
import com.loomcom.symon.devices.Crtc;
import com.loomcom.symon.devices.Memory;
import com.loomcom.symon.devices.Pia;
import com.loomcom.symon.devices.*;
import com.loomcom.symon.exceptions.MemoryRangeException;
import java.io.File;
import java.util.logging.Logger;
@ -78,7 +74,7 @@ public class SymonMachine implements Machine {
this.bus = new Bus(BUS_BOTTOM, BUS_TOP);
this.cpu = new Cpu();
this.ram = new Memory(MEMORY_BASE, MEMORY_BASE + MEMORY_SIZE - 1, false);
this.pia = new Pia(PIA_BASE);
this.pia = new Via6522(PIA_BASE);
this.acia = new Acia6551(ACIA_BASE);
this.crtc = new Crtc(CRTC_BASE, ram);